Abstract

This paper studies key issues for distributed programming in high-level
languages. We discuss the design space and describe an experimental
language, Acute, which we have defined and implemented.

Acute extends an OCaml core to support distributed development,
deployment, and execution, allowing type-safe interaction between
separately-built programs. It is expressive enough to enable a wide
variety of distributed infrastructure layers to be written as simple
library code above the byte-string network and persistent store APIs,
disentangling the language runtime from communication.

This requires a synthesis of novel and existing features:

(1) type-safe marshalling of values between programs;

(2) dynamic loading and controlled rebinding to local resources;

(3) modules and abstract types with abstraction boundaries that are
respected by interaction;

(4) global names, generated either freshly or based on module hashes: at
the type level, as runtime names for abstract types; and at the term
level, as channel names and other interaction handles;

(5) versions and version constraints, integrated with type identity;

(6) local concurrency and thread thunkification; and

(7) second-order polymorphism with a namecase construct.

We deal with the interplay among these features and the core, and
develop a semantic definition that tracks abstraction boundaries, global
names, and hashes throughout compilation and execution, but which still
admits an efficient implementation strategy.